How much Chlorine are you using right now?

[shawmcbigdis]

I'm in Oklahoma City, and this week has been hot (high 90's) and humid. And my pool gets pretty direct sunlight from fairly early morning until about 5:30-6, when it starts to get shade, but isn't totally shaded until after 8PM So not the best conditions for keeping chlorine in the pool. But even considering that it seems like I am using a huge amount of Chlorine right now. My CYA level is only at about 40-50 right now, which is lower than I had last year (about 80) so I know I need to bring that up, but it still seems like I am just pouring bleach down the drain.

Last night around 9PM I was at zero Chlor, so I added 3 gallons of 8.3% bleach. According to Pool Pal, this should have brought me up to about 16. I tested when I got home this evening at just after 5PM. According to the simple Taylor K-1000 test I was at about 2-3. Using the TF-100 test kit, it came back with .5 FC and zero CC, so only .5 total. Not sure why the 2 tests were so far off. regardless, even if I was at 3, to go from 16 down to 3 in 20 hours seems extreme.

I added another 3 pounds of CYA, and 2 more gallons of bleach, and will see where I am at tomorrow.

Other values for reference;

TA = 130 (overshot my mark on that one, but it has stayed stable, and pH is staying stable)
pH = 7.2 (has stayed stable, waiting to get chlorine and CYA in shape before I bump it up)

 

[Texas Splash]

We have similar weather right now - hot & humid. Woo! My CYA is at about 60 or slightly higher and I average about 2.5 FC in 24 hours +/- .5 ppm. Since your FC dropped to zero, you probably should do an overnight (OCLT) test just to ensure you have no algae. I would've done that before the CYA addition, but since it's in already, watch your FC level accordingly. If you fail the OCLT you know you need to SLAM. The sooner the better (link below). If you pass the OCLT and find yourself to be algae-free (no green or cloudiness), then the CYA increase was a good call to get you up to around 60 or so. If you went higher, that may work for you as well, just make sure to test FC each day to remain at your target level. Hope that helps.

 

[shawmcbigdis]

Looks like the addition of the CYA got me to a manageable level. Probably also helped that I replaced my leaking pump, so I wasn't constantly leaking water and CYA. I haven't re-measured my CYA yet, but I only lost about 3 FC in 24 hours.

Looks like I just need to run high CYA's. I way overshot last year, thus why I was running 80+, but it looks like that might actually be the right level for my pool.

 

[Texas Splash]

That's the good thing about knowing your pool and testing your own water. You know your true CYA and understand that if you need to run a higher CYA based on your location (or for those SWG owners) then you know how important it is to maintain that target FC 24/7 and never let it drop below minimum. When it does, oh well... we SLAM at a higher level. Hopefully that never happens, but at least we understand it all and we preserve the FC in the summer from that brutal heat. Good luck!